Long chain linear alpha olefins are hydrocarbons which are always in demand in the chemical industry. Such linear alpha olefins can be converted to corresponding alcohols or aldehydes by conventional "OXO" or hydroformylation processes. Resultant C.sub.14 to C.sub.20 alcohols can further be ethoxylated with ethylene or propylene oxide in the presence of a catalyst to form conventional detergents while lower molecular weight alcohols can be esterified with polyhydrate alcohols to form plasticizers of polyvinyl chloride. Also, long chain linear olefins can be converted to alpha olefin sulfonates by treatment with sulfur trioxide and then used as biodegradable detergents.
It is advantageous to formulate higher olefins as a feed material to such processes as hydroformylation from a lower olefin, such ethylene or butylene. It is also desirable to maximize the specific range of carbon atoms present in the end product. For purposes of utility, it is desirable to acquire the maximum quantity of C.sub.12 to C.sub.18 alpha olefins starting from ethylene.
A basic process for preparing high molecular weight alpha olefins from ethylene is disclosed in U.S. Pat. No. 3,647,906. This process discloses the combinative treatment of oligomerization of ethylene followed by requisite separation, then isomerization and disproportion of light olefins and heavy olefins derived from the separation zone. In this manner, the specific carbon range of alpha olefins is maximized and the refiners profit margin is greatly increased. All of the specific teachings of this patent are herein incorporated by reference. In the procedure where alpha olefins are isomerized to internal olefins, a catalyst is employed which preferably has little or no polymerization or cracking activity. Suitable examples are exemplified as phosphoric acid, bauxite, alumina supported cobalt oxide, iron oxide or manganese.
A variety of catalysts have been employed for conducting isomerization reactions, such as those disclosed in Reissue U.S. Pat. No. 28,137, U.S. Pat. No. 4,217,240, U.S. Pat. No. 4,257,804, U.S. Pat. No. 4,272,409, U.S. Pat. No. 4,016,245, U.S. Pat. No. 4,343,692, U.S. Pat. No. 4,451,572 and U.S. Pat. No. 4,727,203.
The catalysts in the above references are generally prepared according to conventional methods such as impregnation, wherein a carrier is impregnated with a solution of metals; co-precipitation, wherein a carrier compound and metals are simultaneously precipitated; or co-mulling, wherein dry powders are mixed with a suitable extrusion aid such as water and extruded.